Author: S. Janssen
RNAsifter is a non-rigorous filter for the rfam database, that is based on the abstract shape approach.
It exploits the familily specific secondary structure, i.e. it computes shapes for the query-sequence and compares
them to a precalculated shape-index. The exact matches deliver - hopefully only few - candiate families in which
the query-sequence might fold. Membership for the candidate families is checked with the program cmsearch,
afterwards.